Means for regulating electric circuits.



H. LEITNER & R. N. LUCAS. MEANS FOR BEGULATING ELECTRIC OIROUITS.

APPLICATION IILED JARS, 1906. 1,024,793. Patented Apr. 30, 1912.

2 SHEETS-SHEET 1.

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W 4 TNESS/ZS [Nun/(1w H. LEITNER & R. N. LUCAS.

MEANS FOR BEGULATING ELECTRIC CIRCUITS.

APPLICATION FILED JAN. 5, 1905.

- Patented Apr. 30, 1912.

2 SHEETS-SHEET 2 WL'Z/zmses jnuenlorzs }-Klh-u Mimw UNITED STATES PATENTOFFICE.

HENRY LEITNER, OF MAYBURY, WOKING, AND RICHARD NORMAN LUCAS, OF DARTNELLPARK, BYFLEET, ENGLAND.

MEANS FOR REGULATING ELECTRIC CIRCUITS.

Specification of Letters Patent.

Patented Apr. 30, 1912.

To all whomit may concern.

Be it known that we, HENRY LEITNER, residing at Maybury, WVoking, andRICHARD NORMAN Lucas, residing at Lynton, Dartnell Park, Byfleet, bothin the county of Surrey, England, subjects of the King of Great Britain,have invented new and useful Improvements in Means for RegulatingElectric Circuits, of which the following is a specification.

Our invention relates to certain improvements in electric lightingsystems of the class employed on railway trains in which a dynamoconveniently actuated is employed to charge a battery of accumulators,the two together providing current for the electric lamps mounted in thevehicles. In such systems there is a considerable difference in thevoltage or E. M. F. of the battery when it is fully charged andparticularly when it is being still charged by the dynamo and thevoltage of the same when it has been providing the current for the lampsfor some length of time. As these conditions occur successively inpractice, the lamps are un der such circumstances subjected toconsiderable variations of voltage which produces unsatisfactory effectsin the illumination of the carriages and is also prejudicial to thelifeof the lamps. It is also advisable in such systems that means shouldbe provided for\preventing the dynamo continuing to charge theaccumulators when they are already fully charged, as this both wastescurrent and consequently energy and tends to injure the cells.

The object of our invention is to regulate the lighting circuit so as toprevent the variations in voltage of the battery of accumulators underthe circumstances above described causing noticeable variations ofcurrent and illumination in the lamps, and to put the dynamo out ofaction when the battery of accumulators is fully charged and so preventwaste of energy and the injury which continuous overcharging of thecells is likely to cause. In addition we provide means whereby thedynamo is gradually brought into action when the voltage of the batteryof accumulators sinks to some predetermined value in consequence ofhaving supplied current to the lamps while the dynamo is out of action.

According to our invention we employ a variable rheostat of anyconvenient type,

lbut preferably one in which the contacts are arranged circularly, theresistance of this rheostat being designed to be introduced to a greateror less extent in series with the lamps according as the voltage of thebattery of accumulators and the current to the lamps vary. On thisrheostatis mounted a revolving arm carrying a brush adapted to sweepover and make contact with the various contacts of the rheostat andactuated preferably through worm or equivalent gearing by a suitablemotor energized from the lighting circuit. At one position this arm andbrush are so arranged that none of the rheostat resistance is in serieswith the lamps, while at the other end of its travel the whole of thisresistance is in series with them. Consequently it is necessary, as faras the lighting circuit is concerned, that the amount of resistance.introduced in series with the lamps should correspond with the voltageof the battery and the number of lamps turned on. lVe efi'ect this bymeans of a volt meter control arranged in parallel with the lamps. Forwhich purpose we may employ any suitable volt-meter adapted to makesuitable contacts, but we prefer to employ a sole noid attracting a corewhich is arranged to operate a pivoted horizontal bar against the actionof a spring. This pivoted bar carries at either end contacts which makecircuits through the motor operating the rheostat in such a way thatwhen one of these contacts is made the motor rotates in one directionand when the other contact is made it rotates in the opposite direction,this effect being produced either directly, in which case the field ofthe motor is preferably reversed by the contacts made, or the result maybe attained through the intermediary of suitable relays. It will beunderstood that the contacts made by the so-called volt-meter controlare such that when the voltage of the battery rises beyond a certainpredetermined amount the motor is operated to actuate the arm of therheostat so as to increase the amount of resistance in series with thelamps. On the other hand when the voltage sinks-below that predetermined amount, the motor is revolved in the opposite direction andremoves resistance from the lamp circuit. As the voltmeter control is inparallel with the lamps and in series with the rheostat resistance itoperates the apparatus to make the necessary adjustments when a largeror smaller number of lamps are turned on. D

In the arrangement described it is obvious that the motor which operatesthe rheostat would continue to receive current when the rheostat arm wasat either end of its course or travel. In order to avoid this we arrangesuitable contacts in these positions in series with the motor so as tobreak the motor circuit when the arm of the rheostat is in either of itsextreme positions.

The essential features of our invention, however, are concerned withmeans wherebv we can utilize what is practically the same mechanism(namely that above described) employed for regulating the light circuit.and which in itself is similar to other forms of apparatus previouslyproposed or in present use, for the purpose of ctlecting the furtherobjects which we have in view, namely, to throw'the dynamo out of actionwhen the battery of accumulators is fully charged and to re-introduce itand cause it automatically to again generate current and charge thecells when the voltage of the latter has through supplying current tothe lamps or from any other cause sunk to a predetermined value. Toeilect this object we arrange a resistance in series with the windingsof the apparatus which we have above alluded to as the volt-metercontrol. When this resistance is in series with the said volt-metercontrol it causes it to operate on a different scale. This will be mostclearly understood from an example. Supposing that the volt-metercontrol when the above mentioned resistance is not in series with it, isadjusted to, say, 24 volts as the normal, that is to say, with both itscontacts broken. Then it will make one of its contacts for operating themotor in one direction when the voltage rises to, say, 25, while it willmake the other contact when the voltage sinks to, say 23. When now thebefore mentioned resistance is placed in series with it, it will havethe etlect, say, of altering the action so that 30 volts becomes thenormal and it only then makes the one contact when the voltage rises to,say. 31, and the other contact (reversing the motor) when it sinks to,say, 29.

In connection with the rheostat mechanism is arranged a switchpreferably of the trigger type. This switch is arranged to be operatedby the moving arm of the rheostat and brought into one position whenthat arm is in such a position that it cuts out all the resistance fromthe lamp circuit while the same switch is thrown into another positionwhen the rheostat arm is at the opposite end of its travel. that is tosay. in the position in which all the resistance of the rhcostatarranged to be in series with the lamps.

said switch makes one contact and breaks another contact. In the secondposition it breaks the contact which it has previously made and closesor allows to close the other contact which it has previously broken. Thefirst of these contacts is in series with the shunt winding of thedynamo. The second is in parallel with the resistance designed to beplaced in series with the volt meter control. hen the former contact isbroken therefore or bridged by a high resistance (as we prefer toarrange) the dynamo is thrown either entirely out of action or verynearly so. When the second contact is closed the resistance in serieswith the volt meter control is short circuited. This said resistance isalso short cireuited when either of the main lamp switches are closed.

In order that our invention may be the more fully understood, we referto the accompanying two sheets of drawings in which,

Figure 1 shows diagrammatically the elements of our invention applied toa system of lighting in which a differential main generator is arrangedin conjunction with a subsidiary controlling dynamo which latter weakensthe field of the former as the speed of driving increases, the maingenerator being automatically connected to and disconnected from abattery of accumulators by an automatic switch. Figs. 2 and 3 aredetailed views of parts of the mechanism shown diagrammatically in Fig.1.

In the figures the same letters of reference are used to designatecorresponding parts,

but as there are parts which it is necessary to refer to in Figs. 2 and3 not shown in Fig. 1 these extra parts are indicated by additionalletters of reference.

In the drawings:G the armature of the main generator, S the shunt fieldwinding of the same.

M is the series differential winding on the field of the generator.

D is the armature of the demagnetizing or controlling subsidiary dynamo,preferably mounted on the same shaft as G.

S is the shunt field winding of the controlling dynamo. M its seriesfield winding.

R and R are regulating resistances the former of positive temperatureco-etlicient and the latter of negativetemperature coetlicient, arrangedin the system in the manner shown. A A and A are the fine wire fieldwindings, the armature field winding and the coarse wire field windingrespectively of an automatic switch similar to that shown in our PatentNo. 728.942. Hay 26, 1903 for connecting the battery of accumulators 7)with the main generator G and having an oscillating armature. A is thehorizontal lever arm of the said auto- In the first of these positionsthe matic switch which is connected by a link with the oscillatingarmature and makes the three contacts A, A and A in the troughcontaining mercury arranged beneath them which have the effect ofconnecting the various windings of the main generator G and thecontrolling dynamo D i p p thence by l to the shunt winding of thegenerator, thence through resistance R to the other pole of thearmature.

A is a contact made in a mercury trough situated beneath it when thelever A is in its off position, this contact having the effect of shortcircuiting the resistance R when the generator G is at rest and until ithas excited. This takes the current passing through the shunt winding ofthe generator field from a point between said winding and the resistanceR by wires 1 Z and 1 to the contact A thence by line Z, 3, 4 L to thearmature. At the same time, a portion of the current passing the point 9passes by the wire 7, thence by the fine wire field and armature windingof the automatic switch, thence to 3, 4 and L to the generator armature,thus actuating the switch and closing the contacts A, A and A'.. Whenthe contacts A, A, A contact with the mercury in the trough beneath themthe main current passes by L, wires 7, 8 and 9 through the coarse fieldwinding A of the automatic switch, thence by contact A" mercury trough,wires 10, 11 and 12 which i then form a continuation of L to the batteryb. The passage of the main current circular rheostat which are connectedby suitable resistance wire f designed to be introduced into andregulate the circuit of the i lamps 0 c.

g is the arm of the rheostat pivoted as shown and rigid with a wormwheel or disk h which engages with the worm i on the shaft of a motor Mwhich is preferably provided with current from the accumulator circuit.The arm 7 is provided with two brushes and j, the former of which isdesigned to establish contact with the contacts e e as it passes overthem while j is similarly adapted to make contagt with the contacts m mconnected in series "with one another by resistance wire f similar tobut finer in gage than that shown at n is a trigger switch pivoted nearits up per end controlled by a spring and provided with a cam likeprojection which in the position shown in the drawing opens the contact0 0 connecting the leads Z 1*, while the lower end of the switch nbridges or unites the contacts p p, which likewise connect the leads Zand Z". The trigger switch a is adapted to be thrown into the dottedline position by the extreme end of the rotating arm 9 when the lattersweeps around to the opposite end of the crown of rheostat contacts e e.In this dot-ted line position, as will be seen, the contacts 0 0 arebridged or come together while contacts p p are broken and consequentlybridged by the resistance wire j which connects the contacts m m asshown in Fig. 2.

V is the upright solenoid of the device which we have above termed thevolt meter control (details in Fig. This solenoid is adapted to lift theiron core 9 which is pivoted to the pivoted horizontal bar or rod r.This rod is controlled by the adjustable spring V while the bar 7" isprovided with an upright counterpoise 9, its travel being limited bysuitable adjustable vertical stops. The bar 1* carries at its ends twovertical rods or wires 8 and s adapted to dip into and make contact withthe mercury contained in the cups situated immediately beneath them.

V is the resistance which is introduced in series with the solenoid ofthe volt-meter control V as indicated above.

-The contacts s and s and their corresponding mercury cups are soarranged in the circuit and in regard to the motor M by connectionsindicated schematically in Fig. 1, that when 5 makes contact the motor Mis caused to ncvolwe in one direction while when .9 makes contact itrotates in the other direction, thus causing the rheostat arm 9 toinsert resistance in the lamp circuit in the former case and removeresistance therefrom in the latter case. The connections between .9 ands and the motor respectively may be and preferably are efiected throughthe intermediary of relays S and S as in Fig. 1. It is also preferableto arrange contacts at either end of the travel of the lever 7 as shownin Fig. 1 adapted to be opened when the lever g reaches those positions,in this way depriving the motor M of current when it is unable torevolve.

L is the main positive conductor leading from the positive brush of themain genera tor G,

tive brush.

Z and Z are the ends of the shunt winding of the generator G.

It will be seen that the contacts 0 which come together when the switcha is in its dotted line position Fig. 2, short circuit the resistance VBy means of the conductors Z and Z this resistance V is also shortcircnited whenever either of the hand switches (Z or (Z is closed so asto provide current to either of the banks of lamps 0 or 0 a: and g arethe normally closed contacts opened by the rheostat arm 9 when at theextreme ends of its travel which have the effect of depriving the motorM of its car- 35 rent thus stopping the travel of the arm g in thedirection in which it is moving when the circuit is broken, butpermitting it to be operated in the opposite direction. At the firstmovement in the opposite direction the 2 separated contacts w a or y 3as the case may be will be restored to contact. This may be convenientlyaccomplished by making one of the contacts of each series a springactuated or spring contact as indicated in the drawings.

M represents conventionally the armature of the series motor whichoperates the rheostat arm g.

S and S represent two relays energized respectively through the contacts8 and s of the volt-meter control.

M is the field winding of the motor M connected in the manner shown.

lVhen the relay S is'energized through the contact a it pulls over thedouble pole switch M to the left dotted line position where it sendscurrent one way through the field magnet winding M thus causing thearmature M of the motor and with it the 49 'rheostat arm (1 to revolvein one direction. This double pole switch is normally held in the fullline position shown in Fig. 1, free from its contacts by springs Z Z butcan be moved therefrom to the right or left hand dotted line positionsby the relays S and S. The current for energizing the relay S is derivedfrom L passing by way of L, L, S, L contact .9, bar r, wire a" and line25, 2(3 and 17 to L [is this brings the double 59 pole switch to tlnlefthand position the current to the motor, which is also derived from Lwill pass through the armature M, thence by line 20 to the member Z ofthe switch, thence by line 21 to the field winding M of the motor,thence by line 22 to the member Z of the switch, thence by way ofcontacts 9 y to line 19* and wire 3. The contact S energizes the relayS, the current being in 6 this case also derived from L and passing wdirectly through L to the relay S, thence to the contact S, bar 9", wirer, line 25, 26, 17 to L This will bring the double pole switch to theright hand position and the r motor current after passing through thearmature will pass to the member Z of the switch thence through thefield winding of the motor thence by member Z to line 18 to contacts XX, then by line 19 19" to I). This passes the current in a reversedirection through the field winding of the motor and gives it a rotationin the opposite direction and gives the rheostat arm a reverse movement.

The operation of the mechanism is as follows: Let it be assumed that thelights are turned on and the dynamo or generator is charging the batteryof acciunul ators b and supplying some current also to the lights. Thenif the arm 9 of the rheostat is in the full line position Fig. 2 theapparatus operates like an ordinary automatic rheostat. The current tothe lamps enters the rheostat through L and emerges at L. WVith the armg in the said position shown the current does not traverse any of theresistance wire If new the voltage of the battery begins to rise abovethe predetermined point at which the horizontal rod 1' of the volt-metercontrol is horizontal, its core Q is raised and 8 makes contactoperating the relay S to energize the motor so as to rotate the rheostatarm 9 clockwise. This inserts more and more resistance between L and L(and in consequence in series with the solenoid of the volt-metercontrol) until the pull thereof is weakened. and the contact a broken.This will occur at a time when the forces of the spring and solenoid arenearly equal and the rod r is brought into neutral position as shown inFig. 1. This breaks the circuit through the relay S and the spring Zdraws the double pole switch back into normal position and the rheostatarm stops. When the voltage of the battery I) sinks so low as to causethe rod 1" to make contact at s the relay S Will be energized, drawingthe double pole switch to the right hand dotted line position when themotion of the motor will be reversed causing the rheostat arm 9 to moveback toward its original position removing more and more of theresistance wire 7 from between L and L and in consequence from the lampcircuit till the contact .9 is broken (and the motor stops). If one ofthe banks of lamps c or c is turned out by the switches (Z or (Z thevolt-meter control operates so as to cause the rheostat arm g to makethe necessary corresponding adjustment for the variation of current.

Hall the lamps are turned out and the switch a is in the position shownin the drawings full lines, the resistance V is in series with thesolenoid of the volt-meter control V and this latter accordinglyoperates on what has been called the higher scale. When the open circuitvoltage of the battery or of the generator has risen to a certain highpredetermined point, if the battery is injured or is disconnected, thecontact a is made and energizes the motor so tor.

as to bring the rheostat arm 9 around clockwise to the extreme end ofits travel, when it knocks the switch n into the dotted line position(Fig. 2) and breaks the circuit at contacts 3 3 (Fig. 1). stopping themo- In this position of the switch 71 the whole of the resistance wire fin series with the contacts m, Fig. 2, is placed in series with theshunt wire winding of the generator by the opening of the circuit atcontacts p p. This reduces the output of the generator to a few amperes,or less as arranged. At the same time it will be ob- .served that thecontact 0 0 is then made low. oint, say 1.85 volts per cell through suppying current to the lamps. In this way hunting that is to sa alternatelycutting down the output of t e main generator and restori itto its fullvalue again, is prevented. en the voltage sinks to this low value thecontact a is then made and the rheostat arm 9 is operated to movecounterclockwise until 1t comes right around to its extreme posit-ion;knockmg the switch n back to its original position, while as itapproaches the end of its travel itaduall cuts out the resistance wire fso lntroducmg the full power of the generator adually, until the break pp, is closed.

' In t e extreme position of its travel in this direction the arm 9opens the circuit at the contacts a: m (Fig. 1) and so stops the mo-'tor M.

It will be observed that as either of the lamp switches d or d shortcircuit the resistance V by connecting L and Z the voltmeter controlnever operates on what has been called the higher scale except when bothbanks of lamps c and c are turned off.

The whole set of arrangements operate both as an ordinary rheostat tocontrol the lighting circuit when the lights are on, to keep the batteryfully charged, to cut down the output of'the dynamo to little or nothingwhen the batteries are fully charged; they also prevent overcharging thecells and any undue rise of the voltage of the generator if, owing toany accident the connection between it and the battery, or theconnections in the battery itself, are interrupted.

and in what manner the same is to be performed, we declare that what weclaim is 1. In a system of electric lighting, the

combination with the lamps, of a battery of accumulators, in a parallelcircuit with said lamps, a dynamo connected with said battery and lamps,a switch for -making and breaking the circuits through said lam s, arheostat for controlling the lamp circuit, a voltmeter for controllingthe rheostat, two circuits for supplying current to said voltmeter, aresistance in one of said circuits, said lamp switch being constructedto out out the said resistance circuit when the lamp switch is closed,whereby the voltmeter works on a higher scale when the lamps are out ofcircuit, substantially as described.

2. In a system of electric lighting, the

combination with the lamps, of a battery 3. In a system of electriclighting, the

combination with the lamps, of a battery of accumulators for supplyingcurrent to said lamps, an electric generator for supplying current tosaid battery and lamps, a rheostat in the lamp circuit, an electricmotor for operating said rheostat, two circuits of opposite directionsfor operating said m0- tor, a circuit changer for controlling saidcircuits, a volt-meter for controlling said circuit changer, twocircuits of different resistances for supplying current to saidvoltmeter and means for throwing the current of the voltmeter through acircuit of less resistance when the lamps are in circuit, whereby thevolt-meter is caused to operate on a higher and lower scale,substantially as described.

HENRY LEITNER. RICHARD NORMAN LUCAS.

VVitnesses:

JOHN E. BoUsrmLn, C. G. REDFERN.

